Near field communication (NFC) is a set of communications protocols that enable compatible devices to establish radio frequency (RF) communication with each other when they touch or are brought into very close proximity. Typically, NFC devices comprise an NFC controller, an application processor (AP), and a secure element (SE). In a conventional NFC device comprising an NFC controller-centric architecture, the AP communicates directly with the NFC controller using NFC controller interface (NCI) packets, and the NFC controller communicates directly with the SE using host controller protocol (HCP) packets.
In a device comprising a secure, SE-centric NFC architecture, the connection between the AP and the NFC controller is omitted, and communications between the AP and the NFC controller must occur by way of the SE. In order to communicate with the AP, the NFC controller must convey the information in AP-destined NCI packets to the SE using HCP packets, and vice versa.